<http://purl.org/dc/terms/description>
"Fission track dating of zircon and apatite has been used to determine the Cenozoic uplift history of the British Columbia Coast Mountains from 50\u00B0-55\u00B0N. 115 dates were obtained from rocks of variable geographic location and altitude, and the resulting date pattern constrains the movement and deformation of the fission track retention isotherms (175\u00B0C for zircon, 105\u00B0C for apatite) within the crust.\nBecause date-altitude correlations (apparent uplift rates) cannot always be used confidently to estimate actual rates of uplift, a finite difference numerical scheme was formulated to construct models of heat flow, uplift, denudation, and cooling that satisfy not only fission track dates, but also present heat flow, other isotopic dates, geologic considerations, and fission track-derived estimates of paleo-geothermal gradient. In most cases, apparent uplift rates derived from apatite date-altitude correlations are very close to modeled rates of uplift. Zircon-derived apparent rates, however, often exceed modeled rates and reflect post-orogenic cooling a,nd relaxation of isotherms. The relationship of the movement of isotherms to rates of uplift and fission track-derived apparent uplift rates is quantified and discussed.\nOrogenic rapid cooling and uplift occurred from Cretaceous to Eocene time in most of the Coast Mountains. Rates during orogenic uplift were near 1.0 km/Ma, causing\n\nsetting of K-Ar clocks in biotite and hornblende. Uplift rates during the middle Cenozoic ranged from 0.2 km/Ma in the axial region of the mountains between 52\u00B0 and 55\u00B0N to less than 0.1 km/Ma south of 52\u00B0N. The moderate rates north of 52\u00B0N were likely the result of gradual erosion of crust thickened during Eocene orogeny. A thermal origin for this northern uplift is not likely. Rates of uplift south of 52\u00B0N were low despite arc-related volcanic activity during the Oligocene and Miocene.\nAccelerated uplift in the Late Miocene near Bella Coola-Ocean Falls was probably the result of passage of the transverse Anahim Volcanic Belt or hotspot beneath the area about 10 Ma ago, after which uplift slowed.\nRapid Pliocene-Recent uplift south of 52\u00B0N at rates of up to 0.75 km/Ma elevated a broad region creating the present southern Coast Mountains and deforming 7-10 Ma lavas erupted on the mountains' east flank. It is suggested that this uplift resulted from thermal expansion in the mantle related to a westward jump in the locus of late Neogene arc volcanism. The extent of this rapid Pliocene-Recent uplift correlates with the area above the Juan de Fuca-Explorer subducted slab and confirms a relation between continental uplift and plate tectonic setting."@en
<https://open.library.ubc.ca/cIRcle/collections/ubctheses/831/items/1.0052431>